Many documents, such as contracts, applications, receipts, and invoices, are executed by one or more parties physically signing a document using a writing implement. However, such physical signatures are susceptible to forgery and alteration. Furthermore, original documents are also at risk of being lost or misplaced, making later validation of the signatures and the signed documents difficult. Additionally, it can be difficult, if not impossible, to determine and/or prove whether the document was signed by the signatory under duress from the signature alone.